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Diffstat (limited to 'WebCore/platform/graphics/filters/FETurbulence.cpp')
| -rw-r--r-- | WebCore/platform/graphics/filters/FETurbulence.cpp | 386 |
1 files changed, 386 insertions, 0 deletions
diff --git a/WebCore/platform/graphics/filters/FETurbulence.cpp b/WebCore/platform/graphics/filters/FETurbulence.cpp new file mode 100644 index 0000000..bb24362 --- /dev/null +++ b/WebCore/platform/graphics/filters/FETurbulence.cpp @@ -0,0 +1,386 @@ +/* + * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org> + * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org> + * Copyright (C) 2005 Eric Seidel <eric@webkit.org> + * Copyright (C) 2009 Dirk Schulze <krit@webkit.org> + * Copyright (C) 2010 Renata Hodovan <reni@inf.u-szeged.hu> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public License + * along with this library; see the file COPYING.LIB. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301, USA. + */ + +#include "config.h" + +#if ENABLE(FILTERS) +#include "FETurbulence.h" + +#include "CanvasPixelArray.h" +#include "Filter.h" +#include "ImageData.h" + +#include <wtf/MathExtras.h> + +namespace WebCore { + +/* + Produces results in the range [1, 2**31 - 2]. Algorithm is: + r = (a * r) mod m where a = randAmplitude = 16807 and + m = randMaximum = 2**31 - 1 = 2147483647, r = seed. + See [Park & Miller], CACM vol. 31 no. 10 p. 1195, Oct. 1988 + To test: the algorithm should produce the result 1043618065 + as the 10,000th generated number if the original seed is 1. +*/ +static const int s_perlinNoise = 4096; +static const long s_randMaximum = 2147483647; // 2**31 - 1 +static const int s_randAmplitude = 16807; // 7**5; primitive root of m +static const int s_randQ = 127773; // m / a +static const int s_randR = 2836; // m % a + +FETurbulence::FETurbulence(TurbulanceType type, float baseFrequencyX, float baseFrequencyY, int numOctaves, float seed, bool stitchTiles) + : FilterEffect() + , m_type(type) + , m_baseFrequencyX(baseFrequencyX) + , m_baseFrequencyY(baseFrequencyY) + , m_numOctaves(numOctaves) + , m_seed(seed) + , m_stitchTiles(stitchTiles) +{ +} + +PassRefPtr<FETurbulence> FETurbulence::create(TurbulanceType type, float baseFrequencyX, float baseFrequencyY, int numOctaves, float seed, bool stitchTiles) +{ + return adoptRef(new FETurbulence(type, baseFrequencyX, baseFrequencyY, numOctaves, seed, stitchTiles)); +} + +TurbulanceType FETurbulence::type() const +{ + return m_type; +} + +void FETurbulence::setType(TurbulanceType type) +{ + m_type = type; +} + +float FETurbulence::baseFrequencyY() const +{ + return m_baseFrequencyY; +} + +void FETurbulence::setBaseFrequencyY(float baseFrequencyY) +{ + m_baseFrequencyY = baseFrequencyY; +} + +float FETurbulence::baseFrequencyX() const +{ + return m_baseFrequencyX; +} + +void FETurbulence::setBaseFrequencyX(float baseFrequencyX) +{ + m_baseFrequencyX = baseFrequencyX; +} + +float FETurbulence::seed() const +{ + return m_seed; +} + +void FETurbulence::setSeed(float seed) +{ + m_seed = seed; +} + +int FETurbulence::numOctaves() const +{ + return m_numOctaves; +} + +void FETurbulence::setNumOctaves(bool numOctaves) +{ + m_numOctaves = numOctaves; +} + +bool FETurbulence::stitchTiles() const +{ + return m_stitchTiles; +} + +void FETurbulence::setStitchTiles(bool stitch) +{ + m_stitchTiles = stitch; +} + +// The turbulence calculation code is an adapted version of what appears in the SVG 1.1 specification: +// http://www.w3.org/TR/SVG11/filters.html#feTurbulence + +FETurbulence::PaintingData::PaintingData(long paintingSeed, const IntSize& paintingSize) + : seed(paintingSeed) + , width(0) + , height(0) + , wrapX(0) + , wrapY(0) + , channel(0) + , filterSize(paintingSize) +{ +} + +// Compute pseudo random number. +inline long FETurbulence::PaintingData::random() +{ + long result = s_randAmplitude * (seed % s_randQ) - s_randR * (seed / s_randQ); + if (result <= 0) + result += s_randMaximum; + seed = result; + return result; +} + +inline float smoothCurve(float t) +{ + return t * t * (3 - 2 * t); +} + +inline float linearInterpolation(float t, float a, float b) +{ + return a + t * (b - a); +} + +inline void FETurbulence::initPaint(PaintingData& paintingData) +{ + float normalizationFactor; + + // The seed value clamp to the range [1, s_randMaximum - 1]. + if (paintingData.seed <= 0) + paintingData.seed = -(paintingData.seed % (s_randMaximum - 1)) + 1; + if (paintingData.seed > s_randMaximum - 1) + paintingData.seed = s_randMaximum - 1; + + float* gradient; + for (int channel = 0; channel < 4; ++channel) { + for (int i = 0; i < s_blockSize; ++i) { + paintingData.latticeSelector[i] = i; + gradient = paintingData.gradient[channel][i]; + gradient[0] = static_cast<float>((paintingData.random() % (2 * s_blockSize)) - s_blockSize) / s_blockSize; + gradient[1] = static_cast<float>((paintingData.random() % (2 * s_blockSize)) - s_blockSize) / s_blockSize; + normalizationFactor = sqrtf(gradient[0] * gradient[0] + gradient[1] * gradient[1]); + gradient[0] /= normalizationFactor; + gradient[1] /= normalizationFactor; + } + } + for (int i = s_blockSize - 1; i > 0; --i) { + int k = paintingData.latticeSelector[i]; + int j = paintingData.random() % s_blockSize; + ASSERT(j >= 0); + ASSERT(j < 2 * s_blockSize + 2); + paintingData.latticeSelector[i] = paintingData.latticeSelector[j]; + paintingData.latticeSelector[j] = k; + } + for (int i = 0; i < s_blockSize + 2; ++i) { + paintingData.latticeSelector[s_blockSize + i] = paintingData.latticeSelector[i]; + for (int channel = 0; channel < 4; ++channel) { + paintingData.gradient[channel][s_blockSize + i][0] = paintingData.gradient[channel][i][0]; + paintingData.gradient[channel][s_blockSize + i][1] = paintingData.gradient[channel][i][1]; + } + } +} + +inline void checkNoise(int& noiseValue, int limitValue, int newValue) +{ + if (noiseValue >= limitValue) + noiseValue -= newValue; + if (noiseValue >= limitValue - 1) + noiseValue -= newValue - 1; +} + +float FETurbulence::noise2D(PaintingData& paintingData, const FloatPoint& noiseVector) +{ + struct Noise { + int noisePositionIntegerValue; + float noisePositionFractionValue; + + Noise(float component) + { + float position = component + s_perlinNoise; + noisePositionIntegerValue = static_cast<int>(position); + noisePositionFractionValue = position - noisePositionIntegerValue; + } + }; + + Noise noiseX(noiseVector.x()); + Noise noiseY(noiseVector.y()); + float* q; + float sx, sy, a, b, u, v; + + // If stitching, adjust lattice points accordingly. + if (m_stitchTiles) { + checkNoise(noiseX.noisePositionIntegerValue, paintingData.wrapX, paintingData.width); + checkNoise(noiseY.noisePositionIntegerValue, paintingData.wrapY, paintingData.height); + } + + noiseX.noisePositionIntegerValue &= s_blockMask; + noiseY.noisePositionIntegerValue &= s_blockMask; + int latticeIndex = paintingData.latticeSelector[noiseX.noisePositionIntegerValue]; + int nextLatticeIndex = paintingData.latticeSelector[(noiseX.noisePositionIntegerValue + 1) & s_blockMask]; + + sx = smoothCurve(noiseX.noisePositionFractionValue); + sy = smoothCurve(noiseY.noisePositionFractionValue); + + // This is taken 1:1 from SVG spec: http://www.w3.org/TR/SVG11/filters.html#feTurbulenceElement. + int temp = paintingData.latticeSelector[latticeIndex + noiseY.noisePositionIntegerValue]; + q = paintingData.gradient[paintingData.channel][temp]; + u = noiseX.noisePositionFractionValue * q[0] + noiseY.noisePositionFractionValue * q[1]; + temp = paintingData.latticeSelector[nextLatticeIndex + noiseY.noisePositionIntegerValue]; + q = paintingData.gradient[paintingData.channel][temp]; + v = (noiseX.noisePositionFractionValue - 1) * q[0] + noiseY.noisePositionFractionValue * q[1]; + a = linearInterpolation(sx, u, v); + temp = paintingData.latticeSelector[latticeIndex + noiseY.noisePositionIntegerValue + 1]; + q = paintingData.gradient[paintingData.channel][temp]; + u = noiseX.noisePositionFractionValue * q[0] + (noiseY.noisePositionFractionValue - 1) * q[1]; + temp = paintingData.latticeSelector[nextLatticeIndex + noiseY.noisePositionIntegerValue + 1]; + q = paintingData.gradient[paintingData.channel][temp]; + v = (noiseX.noisePositionFractionValue - 1) * q[0] + (noiseY.noisePositionFractionValue - 1) * q[1]; + b = linearInterpolation(sx, u, v); + return linearInterpolation(sy, a, b); +} + +unsigned char FETurbulence::calculateTurbulenceValueForPoint(PaintingData& paintingData, const FloatPoint& point) +{ + float tileWidth = paintingData.filterSize.width(); + ASSERT(tileWidth > 0); + float tileHeight = paintingData.filterSize.height(); + ASSERT(tileHeight > 0); + // Adjust the base frequencies if necessary for stitching. + if (m_stitchTiles) { + // When stitching tiled turbulence, the frequencies must be adjusted + // so that the tile borders will be continuous. + if (m_baseFrequencyX) { + float lowFrequency = floorf(tileWidth * m_baseFrequencyX) / tileWidth; + float highFrequency = ceilf(tileWidth * m_baseFrequencyX) / tileWidth; + // BaseFrequency should be non-negative according to the standard. + if (m_baseFrequencyX / lowFrequency < highFrequency / m_baseFrequencyX) + m_baseFrequencyX = lowFrequency; + else + m_baseFrequencyX = highFrequency; + } + if (m_baseFrequencyY) { + float lowFrequency = floorf(tileHeight * m_baseFrequencyY) / tileHeight; + float highFrequency = ceilf(tileHeight * m_baseFrequencyY) / tileHeight; + if (m_baseFrequencyY / lowFrequency < highFrequency / m_baseFrequencyY) + m_baseFrequencyY = lowFrequency; + else + m_baseFrequencyY = highFrequency; + } + // Set up TurbulenceInitial stitch values. + paintingData.width = roundf(tileWidth * m_baseFrequencyX); + paintingData.wrapX = s_perlinNoise + paintingData.width; + paintingData.height = roundf(tileHeight * m_baseFrequencyY); + paintingData.wrapY = s_perlinNoise + paintingData.height; + } + float turbulenceFunctionResult = 0; + FloatPoint noiseVector(point.x() * m_baseFrequencyX, point.y() * m_baseFrequencyY); + float ratio = 1; + for (int octave = 0; octave < m_numOctaves; ++octave) { + if (m_type == FETURBULENCE_TYPE_FRACTALNOISE) + turbulenceFunctionResult += noise2D(paintingData, noiseVector) / ratio; + else + turbulenceFunctionResult += fabsf(noise2D(paintingData, noiseVector)) / ratio; + noiseVector.setX(noiseVector.x() * 2); + noiseVector.setY(noiseVector.y() * 2); + ratio *= 2; + if (m_stitchTiles) { + // Update stitch values. Subtracting s_perlinNoiseoise before the multiplication and + // adding it afterward simplifies to subtracting it once. + paintingData.width *= 2; + paintingData.wrapX = 2 * paintingData.wrapX - s_perlinNoise; + paintingData.height *= 2; + paintingData.wrapY = 2 * paintingData.wrapY - s_perlinNoise; + } + } + + // The value of turbulenceFunctionResult comes from ((turbulenceFunctionResult * 255) + 255) / 2 by fractalNoise + // and (turbulenceFunctionResult * 255) by turbulence. + if (m_type == FETURBULENCE_TYPE_FRACTALNOISE) + turbulenceFunctionResult = turbulenceFunctionResult * 0.5f + 0.5f; + // Clamp result + turbulenceFunctionResult = std::max(std::min(turbulenceFunctionResult, 1.f), 0.f); + return static_cast<unsigned char>(turbulenceFunctionResult * 255); +} + +void FETurbulence::apply(Filter* filter) +{ + if (!effectContext()) + return; + + IntRect imageRect(IntPoint(), resultImage()->size()); + if (!imageRect.size().width() || !imageRect.size().height()) + return; + + RefPtr<ImageData> imageData = ImageData::create(imageRect.width(), imageRect.height()); + PaintingData paintingData(m_seed, imageRect.size()); + initPaint(paintingData); + + FloatRect filterRegion = filter->filterRegion(); + FloatPoint point; + point.setY(filterRegion.y()); + int indexOfPixelChannel = 0; + for (int y = 0; y < imageRect.height(); ++y) { + point.setY(point.y() + 1); + point.setX(filterRegion.x()); + for (int x = 0; x < imageRect.width(); ++x) { + point.setX(point.x() + 1); + for (paintingData.channel = 0; paintingData.channel < 4; ++paintingData.channel, ++indexOfPixelChannel) + imageData->data()->set(indexOfPixelChannel, calculateTurbulenceValueForPoint(paintingData, point)); + } + } + resultImage()->putUnmultipliedImageData(imageData.get(), imageRect, IntPoint()); +} + +void FETurbulence::dump() +{ +} + +static TextStream& operator<<(TextStream& ts, const TurbulanceType& type) +{ + switch (type) { + case FETURBULENCE_TYPE_UNKNOWN: + ts << "UNKNOWN"; + break; + case FETURBULENCE_TYPE_TURBULENCE: + ts << "TURBULANCE"; + break; + case FETURBULENCE_TYPE_FRACTALNOISE: + ts << "NOISE"; + break; + } + return ts; +} + +TextStream& FETurbulence::externalRepresentation(TextStream& ts, int indent) const +{ + writeIndent(ts, indent); + ts << "[feTurbulence"; + FilterEffect::externalRepresentation(ts); + ts << " type=\"" << type() << "\" " + << "baseFrequency=\"" << baseFrequencyX() << ", " << baseFrequencyY() << "\" " + << "seed=\"" << seed() << "\" " + << "numOctaves=\"" << numOctaves() << "\" " + << "stitchTiles=\"" << stitchTiles() << "\"]\n"; + return ts; +} + +} // namespace WebCore + +#endif // ENABLE(FILTERS) |